Jaguar's XKR-R: The Cat with the Sharpest Claws

09 November 2001

For the first time in North America, Jaguar showed a development of its XKR Coupe sports car, the XKR-R Performance Prototype.

The vehicle debuted at the Specialty Equipment Market Association (SEMA)'s trade show here. This also is the first time that Jaguar North America has had an official presence at the SEMA show, the largest aftermarket component show in the world. ""From our earliest days under company founder Sir William Lyons, Jaguar cars have always been about the excitement of driving,"" said Mike Massey, development manager for Jaguar's Special Vehicle Operations (SVO), based in Coventry, England. ""The XKR-R Performance Prototype was produced to show just how far we could go with the basic XKR architecture, with the addition of a few modifications. We aimed to build a road car -- comfortable, easy to live with and very drivable -- that could acquit itself with the very best track cars. I think we've succeeded.""

To meet the SVO team's design brief, the car was built from the ground up using new, modified and custom-built parts. Not a single component escaped the team's attention in the metamorphosis from stock XKR to the unique XKR-R, from the revised shape of the front bumper to the quad-outlet exhaust. The team started the process of strengthening the car by seam-welding the unibody. To enhance rigidity, the front suspension crossbeam was mounted to the underbody using aluminum bushings, rather than the standard rubber items. The steering rack is shared with the XK180 show vehicle -- another SVO creation -- and gives a fast 2.2 turns lock-to-lock. The custom Eibach springs with fully adjustable racing-type remote-reservoir shock absorbers are specific to this vehicle.

SVO began strengthening the rear by installing an eight-point roll-bar. The rear suspension is greatly revised from the stock XKR, and features the entire rear floor area from the S-TYPE sedan, along with the rear axle from an S-TYPE. As Massey explains, ""Use of the S-TYPE axle allowed us a greater range of adjustment and tuning, keeping in mind the dual personality of the car.""

The XKR-R rides lower than a stock XK8 by 30 millimeters, and the purposeful look of the car is further accentuated by the fitting of Jaguar's own 20-inch BBS-sourced R-Performance wheels. The wheels are filled with Jaguar's Brembo-sourced R-Performance brake calipers and cross-drilled rotors. With the addition of specially produced front and rear bumpers, sculptured rocker panels and trunk lid spoiler, the car looks more purposeful and aggressive, yet retains that Jaguar elegance.

Inside, the XKR-R is a showcase for planned R-Performance dealer-installed options and one-off components. Occupant protection is paramount, so, in addition to the rollbar, SVO installed Recaro racing seats and four-point seatbelts. The instruments are ringed with R-Performance aluminum bezels, the dash is trimmed with carbon fiber, rather than Jaguar's usual wood, and the pedals receive aluminum covers for sure footing in fast driving.

But the real fun is under the louvered hood. Twin carbon-fiber air intakes, enlarged intercoolers and an increased supercharger crank-pulley ratio increase the stock car's 370-horsepower toward SVO's 450-horsepower target. The car currently produces about 400-horsepower, with 400 lb./ft. of torque.

Behind the engine, SVO replaced the stock five-speed automatic transmission with a customized Tremec T-56 six-speed manual unit, similar to that found in the Dodge Viper and Chevrolet Corvette. The T56 is a stout unit, and paired with an AP Racing twin-plate clutch, is a suitable partner for the XKR-R's power and torque. So will the XKR-R Performance Prototype ever see production? It is currently both Jaguar and SVO's fastest parts test-bed and serves as an example of the skills and talents of the company's designers, craftspeople and engineers. It was intended to stretch the limits of the XK chassis and engine, to prove the performance that is latent in the car. Certainly, some of the R-Performance items are either already available or will soon be. Interest within the company to move it toward production is high, but at this time, no final decision has been rendered as to what the future holds for the car.